The state’s plans to curb the spread of avian malaria, which is decimating native bird populations, has been given a second green light by Hawaiʻi’s Intermediate Court of Appeals.

The Department of Land and Natural Resources and American Bird Conservancy first made its plan to release bioengineered, infertile mosquitoes in East Maui in 2023, using a technique akin to birth control that breeds infertile male mosquitoes with local female populations to halt the population’s growth.

Mosquito carriers of avian malaria have been blamed for the extinction of several native bird species, including pushing many Hawaiian honeycreeper species to the brink of extinction.

But state plans have faced two years of pushback from Maui nonprofit Hawaiʻi Unites, which sued the state in 2023, claiming it has not followed due process in calculating potential environmental ramifications. The court found in favor of the state last year, a decision the Maui nonprofit appealed.

“This is an emotional issue for people,” DLNR director Dawn Chang said in a press release. “These birds are part of our cultural and ecological heritage, and I think everyone wants to see them protected in the right way.”

The technique in question has been used to control mosquito populations worldwide but Hawaiʻi Unites argued last year that the wrong standards were applied.

“This decision reinforces what we’ve known all along — Hawai‘i is on solid legal and scientific ground in its effort to save native forest birds from extinction,” said Maxx Phillips, an attorney representing American Bird Conservancy. “The courts have once again made clear that we won’t stand by while avian malaria pushes these irreplaceable species to the brink. Our manu deserve a fighting chance.”